Since we have no idea where you are located, it's hard to say. A lot of the country experienced a long and very cold winter and that can affect plants emerging from dormancy in different ways. Depending on the type of hydrangea you have, winter could have killed back all the topgrowth but the roots themselves may be fine and new growth is just slow to emerge.

Blue flowers would indicate some sort of macrophylla or bigleaf hydrangea. These types are most sensitive to cold winters and can often die back to the roots. I'd be a bit more patient but you might want to let us know where you are for more detail.

Iam in Ohio. zone 5. I put them in a pot with the holes for the roots last year. They are big leaf. I guess I will wait and see what come up for awhile. Wont cut anything till it does, if it does. Thank you.( We did have a very cold wet winter here in Dayton)

Were the pots left outdoors all winter? If so, then it is very likely the plant is dead. Containerized plants cannot withstand the same degree of cold as those planted in the ground. The recommendation is to select plants at least 2 zones hardier than your own for success but not even that is a guarantee if the container soil freezes solid.